Space heat exchange unit



Jan. 19, 1965 A. BOYSEN ETAL 3,166,121

SPACE HEAT EXCHANGE UNIT Filed Feb. 8, 1962 FIG. 2.

INVENTORS.

ARN; BOYSEN BIBGER LARKFELDT GOSTA STEINHOLTZ BY 2 /J ATTYS.

United States Patent 7" 3,166,121 SPACE HEAT EXCHANGE UNIT Arne Boy sen, Lidingo, and i irger Liirirteidt and Steinhoitz, .loniroping, Sweden, assignors to Ahtiehoiaget Svensira Flaaafahrihen, Stochhoim, Sweden Fiied Feb. 8, 1962, Ser. No. 171,93tl 1 Claim. (Cl. 165-35) The present invention relates to a space heat exchange unit designed to cool or heat the ventilating air and connected to a common ventilating system.

With room units designed to cool the ventilating air, the heat exchanging surface for a given cooling load must be large, as the temperature of the cooling medium cannot be substantially lower than the temperature of the ventilating air or condensation will occur in the heat exchanger. If the same heat exchanger element is to be utilized for heating'which is more and more usual in present practicethe quantity of heating medium must be considerably less than the cooling medium if excess capacity is to be avoided, or alternatively the temperature of the heating medium in relation to that of the ventilating air must be limited. Both these alternatives involve a complication of the system and, in addition, have the disadvantage of a divergence from the ideal value (quantity or temperature of medium) and a substantial eviation from the desired capacity. It is an object of the present invention to eliminate these difiiculties and disadvantages by means of a construction in which the surface utilized for heat exchanging is reduced on changeover from cooling to heating.

The invention is characterized by the arrangement that the heat exchangers of the room units are equipped with a change-over valve, by means of which the cooling or heating medium can be caused to fiowthrough a part of or through the whole heat exchanger. In cases where the heat exchanger according to the invention is designed to be connected to a system in which media with two difierent temperature levels is caused to circulate alternately, the change-over valve according to a suitable embodiment is constructed to cause the medium to flow through a part of the heat exchanger only, when medium at a temperature approximately equal to one temperature level is circulated, and through the heat exchanger as a whole, when medium at a temperature approximatelyequal to the other temperature level is caused to circulate through theheat exchanger.

The invention will now be described more in detail with reference to the accompanying drawing in which:

FIG. 1 is a schematic view of a fluid heat exchange tube system embodying the invention;

FIG. 2 is an enlarged view, partly in section, of a bypass tube controlling valve shown in FIG. 1.

In the drawing, 1 designates the inlet and 2 the outlet of a tubular element 3 arranged in serpentine coils. In the case shown, this is constructed as an element in which the serpentine part is in the form of a number of coils arranged beside each other. 4 designates a three-way valve fitted in one of the coils and connected to the other part of the element by means of a by-pass line 5. When the valve is set for straight through flow, the medium passes through the whole element, whilst the second position of the valve causes it to pass from the first coil of the element via the by-pass line to the last'coil of the element, i.e. to flow through only a small part of the element. In the case shown, the three-way valve is automatic and is fitted with an actuating motor 6 which is controlled by a temperature sensing element 7 inserted in the inlet of the element;

vWhat we claim is:

A space heat exchange unit comprising a heat exchange fluid conducting tube having an inlet end, and outlet end, and an extended loop length'in series between the inlet and outlet ends and having adjacent passes near the inlet and outlet ends, a by-pass tube arranged between said adjacent passes and communieating therewith in a position to short out a certain portion or" the total heat exchange tube length and leave in a shortened length of the heat exchange tube, a three-way by-pass valve located at the junction of said by-pass tube and one of said passes, said by-pass valve being formed and arranged to open the full length of the heat exchange tube to the flow of heat exchange fluid therethrough and fully close said by-passttube, when a cooling medium is supplied to the heat exchange unit, or to fully close said certain portion of the heat exchange tube and open said by pass tube for the flow of heat exchange fiuid therethrough and through said shortened length of heat exchange tube, when a heating medium is supplied to the heat exchange unit, and means located at the inlet end of'said tube and responsive to the temperature of the heat exchange fluid at said inlet end for controlling the two positions of said .by-pass .valve.

References Cited by the Examiner UNITED STATES PATENTS 2,337,789 12/43 Whitney 16540 2,357,706 9/44 Toepperwein 165-40 2,739,792

CHARLES SUKALO, Primary Examiner.

PERCY L. PATRICK, Examiner.

3/56 Blum V l-22 

